ESTRO 2024 - Abstract Book

S651

Clinical - Breast

ESTRO 2024

Fibrosis

211 (84%)

38 (15%)

2

0

(1%)

Pain

230 (91.6%)

20

1

0

(8%)

(0.4%)

Telangiectasia

248 (98.8%)

3

0

0

(1.2%)

Results:

Median follow-up was 38.6 (4.8 – 65.5)months(m). All pts were evaluable for acute toxicity. Late toxicity and cosmesis data were available for 251 pts. Acute and late toxicity are summarized in Table1. Only 3 pts experienced ≥ G3 acute toxicity and only 1≥ G3 late toxicity. Cosmetic outcome according Harvard breast cosmesis scale was available for 241 pts: excellent 41.5%, good 47.5%, fair 8%, poor 3%. Fourty pts (16%) had liponecrosis, evaluated by mammography, ultrasound or MRI. At the last follow-up cardiac events were diagnosed in 4 pts (3 cases of Trastuzumab-induced pericarditis and 1 case of post-CHT heart failure) and lung fibrosis with symptomatic pneumonitis in 2 cases. Raw local control was 98.8%. Only 3 pts (1.2%) had LR(1 TN, 1 Luminal B HER2+, 1 Luminal B HER2-) and 5 pts(2%) (3 Luminal B HER2-, 1 TN, 1 Luminal A), had distant progression(4 bone metastasis, 1 axillar lymph node), at median TTP of 38.4(22.8-44.5) m. Four pts were dead at the last follow-up (2 old age, 1 comorbidity, 1 metastatic lung tumor diagnosed 21m after RT). Median OS was 44.5 (8.9-73.9) m.

Conclusion:

In our experience HRT+SIB was feasible with low acute and late toxicity profile, highly satisfying cosmetic outcome and excellent local control. A longer follow-up is necessary to confirm these results.

Keywords: hypofractionation, simultaneous integrated boost